Semiconductor device, method of manufacturing the same, and substrate for manufacturing the same

Abstract

A semiconductor device includes a substrate, a buffer layer that is formed with an aluminum nitride layer on the substrate and has a film thickness of 5 nm to 40 nm, an operating layer that is formed with a gallium nitride-based semiconductor on the buffer layer, and a control electrode that is formed on the operating layer.

1 . A method of manufacturing a semiconductor device, comprising the steps of:
 forming a buffer layer on a substrate by metal organic chemical vapor deposition, the buffer layer being an aluminum nitride layer having a film thickness of 5 nm to 40 nm;   forming an operating layer on the buffer layer by metal organic chemical vapor deposition, the operating layer being formed with a gallium nitride-based semiconductor; and   forming a control electrode on the operating layer.   
   
   
       2 . The method as claimed in  claim 1 , wherein the film thickness of the buffer layer is 5 nm to 25 nm. 
   
   
       3 . The method as claimed in  claim 1 , wherein the substrate is one of a silicon carbide substrate, a sapphire substrate, and a gallium nitride-based semiconductor substrate. 
   
   
       4 . The method as claimed in  claim 1 , wherein the operating layer includes a gallium nitride layer that is formed on the buffer layer and has a film thickness of 0.5 μm to 2.0 μm. 
   
   
       5 . The method as claimed in  claim 1 , wherein the buffer layer is formed under conditions that a pressure is in a range of 3.3 kPa to 101.3 kPa, a V/III ratio is a range of 1000 to 100000 and a substrate temperature is a range of 800 degree centigrade to 1400 degree centigrade. 
   
   
       6 . The method as claimed in  claim 1 , wherein:
 the buffer layer is formed under conditions that   a pressure is 6.7 kPa, a V/III ratio is 10000 and   a substrate temperature is 1300 degree centigrade; and
 the film thickness of the buffer layer is 18 nm. 
   
   
   
       7 . The method as claimed in  claim 1 , wherein:
 the opening layer is formed under conditions that a pressure is 13.3 kPa, a V/III ratio is 5000;   the film thickness of the buffer layer is 1.5 μm; and   the operating layer is a gallium nitride layer.   
   
   
       8 . The method as claimed in  claim 4 , wherein:
 the operating layer is formed under conditions that a pressure is in a range of 3.3 kPa to 101.3 kPa, a V/III ratio is a range of 1000 to 100000 and a substrate temperature is a range of 1000 degree centigrade to 1400 degree centigrade; and   the operating layer is a gallium nitride layer.